US 3803862 A
A refrigerator particularly adapted to the manufacture and storage of ice pieces comprising a below-freezing compartment containing an automatic ice maker and an evaporator including a first section for cooling the compartment and a second section heat exchanged with the ice maker mold.
Description (OCR text may contain errors)
United States Patent [191 Schumacher REFRIGERATOR INCLUDING AUTOMATIC ICE MAKER  Inventor: Frank A. Schumacher, Louisville,
 Assignee: General Electric Company,
Louisville, Ky.  Filed: Dec. 13, 1972  App]. No.: 314,695
 US. Cl 62/137, 62/156, 62/526  Int. Cl. F25c 1/06  Field of Search 62/137, 135, 156, 526
 References Cited UNITED STATES PATENTS 2,511,125 6/1950 Phillip 62/526 3,009,336 11/1961 Baystonct a1. 62/135 3,359,747 12/1967 Linstromberg..... 62/135 2,545,558 3/1951 Russell et a1 62/135 3,277,661 10/1966 Dwyer 62/135 Apr. 16, 1974,
Primary Examiner-William E. Wayner Assistant Examiner-William E. Tapolcai, Jr. Attorney, Agent, or Firm-Francis H. Boos, Jr.
[5 7] ABSTRACT A refrigerator particularly adapted to the manufacture and storage of ice pieces comprising a below-freezing compartment containing an automatic ice maker and an evaporator including a first section for cooling the compartment and a second section heat exchanged with the ice maker mold.
Means are provided for periodically conducting hot compressed refrigerant through the evaporator to aid in melting the ice pieces free of the mold and to defrost the first evaporator section. The operation of the refrigeration system and the ice maker are controlled by a single thermostat associated with the ice maker mold.
4 Claims, 5 Drawing Figures BACKGROUND OF THE INVENTION The present invention relates to a household refrigerator equipped with an automatic ice maker of the type described and claimed in US. Pat. Nos. 3,163,017- Baker et al. and 3,331,215-Shawin which the ice harvesting cycles are temperature initiated and heat is applied to the ice maker mold during the harvesting cycle to aid in the release and discharge of ice pieces therefrom. While automatic ice makers are usually provided in automatic defrost refrigerators which also require means for heating the evaporator to defrost temperatures, the control means for timing the defrost operation of the refrigeration system have been separate from the controls for initiating and timing the ice maker in its ice harvesting cycles.
SUMMARY OF THE INVENTION In accordance with the illustrated embodiment of the invention, there isprovided an ice service refrigerator comprising a below-freezing or freezer compartment. containing an'ice maker and'an evaporator including a section in heat exchange relationship with the ice maker mold and a second or main section mounted in the upper portion of the freezer compartment for maintaining sub-freezing temperatures in that compartment. The evaporator sections form part of a refrigerant circuit including a conventional hot gas defrost circuit for periodically conveying hotgaseous refrigerant through theevaporator sections. The hot gas defrost circuit includes a solenoid operatedvalve and the ice maker includes a motor-driven, ice ejecting and timed control circuit, both the solenoid valve and the motor beingcontrolled by a single thermostat responsive to the freezing of water in the ice maker mold whereby the freezer evaporator, including the section in contact with the ice maker mold, is warmed to defrosting temperatures during each. harvesting cycle operation of the ice maker.
BRIEF DESCRIPTION oFrnE DRAWINGS.
With reference to the accompanying drawings:
FIG. I is a front. elevational view of the refrigerator of the present invention with. the doors removed;
FIG. 2 is a sectional view taken generally along line 2-2 of FIG. 1;
FIG. 3 illustrates certain components of an ice maker of the type employed in the practice of the present invention;
FIG. 4 is a schematic diagram of the refrigerant circuit employed in the practice of the present invention; and
FIG. 5 is a schematic wiring diagram of the electrical circuitry employed in the practice of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT With particular reference to FIGS. 1 and 2 of the drawing, the refrigerator comprises a rectangular cabinet including insulated outer walls and a partition 1 dividing the cabinet into a freezer compartment 2 and a fresh food compartment 3 in side-by-side relationship. The access openings to these compartments are respectively closed by suitable doors including a freezer compartment door 4. The rear wall 6 of the freezer compartment has a re-entrant portion 7 adjacent the lower end of the wall forming an area or housing outside the freezer compartment 2 for housing the compressor component 8 of the refrigeration system. A condenser 9 is supported on the rear wall of the cabinet.
The fresh food compartment 3 contains a removable water storage reservoir or tank 11 suitably supported adjacent the top thereof and one or more storage shelves 10.
The freezer compartment 2 contains an automatic ice maker generally indicated by the numeral 12. This ice maker is of the type described and claimedin the aforementioned Baker et al and Shaw patents and, as illustrated particularly in FIG. 3 of the drawing, comprises a mold IS-containing a plurality of mold cavities 16 for receiving water from a water supply conduit 17. Ejection pads 18 at the bottom of each of the cavities are provided for mechanically raising and ejecting ice pieces from the cavities, these pads being operated through a lever mechanism 19 driven by a motor 20 which, as is described in the aforementioned Baker et al and Shaw patents, also drives a timing mechanism for controlling the operation of the ice maker through a harvesting cycle which comprises ejecting the ice pieces from the mold, returning the pads to their normalposition at the bottom of the cavities and introducing a fresh charge of water into the mold.
In the illustrated embodiment of the invention the ice maker 12 is supported above an ice storage receptacle 22 mounted on thefreezer door 4. The freezer compartment 2 also includes an evaporator comprising a section 23 for maintaining the freezer compartment at the desired below-freezing temperature and an ice maker section 24 which, as is illustrated in FIG. 3 of the drawing, is in heat exchange contact with the lower portion of the ice maker mold 15.
The section 23 of the evaporator is disposed along the top wall of the freezer compartment and comprises a slanting portion 27 sloping downwardly from adjacent the partition 1 and terminating in a depending vertical portion 28 having at the bottom thereof a defrost water drain trough 29. This evaporator section 23 is preferably of a rollbond construction comprising a plate having formed therein a plurality of refrigerant passages.
A fan 30 may be provided below the evaporator section 23 for improving the air circulation. For refrigerating the fresh food compartment 3 there is provided an air passage 32 in the upper portion of the partition 1 for conveying cooled air from the evaporator and freezer compartment into the fresh food compartment 3. A
compartment to the freezer compartment. Adjustment of the size of this opening controls the temperature of the fresh food compartment whereas the freezer control is non-adjustable and within the design parameters and bimetal control limits. The fan 30 aids in the circulation of air through these passages.
While the water supply line 17 may be connected to the usual household water supply through a suitable valve, in the illustrated embodiment of the invention water for the ice maker is contained within the reservoir 11 positioned in the upper part of the fresh food compartment and the reservoir is connected through a pump 36 and a supply line 37 to the ice maker water supply conduit 17.
The evaporator forms part of a refrigerant circuit shown in FIG. 4 and including the compressor 8, condenser 9, suitable flow restricting means 38 and the evaporator sections 24 and 23 connected in closed series flow relationship. The refrigeration system also includes means for conveying warm compressed refrigerant directly from the condenser outlet to the inlet of the evaporator or, more specifically, bypassing the flow restrictor 38. The hot gas conduit indicated by the numeral 40 includes a normally closed solenoid valve 41.
In accordance with the present invention, cooling of the mold to freeze the water contained in the mold cavities is primarily accomplished by the refrigerant flowing through the evaporator section 24 while thawing of the bond between the ice pieces and the cavity walls during the harvesting cycle is accomplished by the warming action of the hot compressed refrigerant bypassed through the hot gas conduit 40 and into the evaporator sections when valve 41 is open. In further accordance with the present invention, the usual ice maker mold thermostat 45, which initiates an ice harvesting cycle upon sensing a predetermined belowfreezing mold temperature, is employed also to control the valve 41 for warming the mold to an ice releasing temperature and for defrosting the evaporator section 23 during each ice making cycle.
The electrical control circuitry for accomplishing this result is shown in FIG. 5 of the drawing. The compressor 8 is connected directly across the supply lines L1, L2 so that it runs continuously. The ice maker motor is connected across the lines L1, L2 through contact 52 of the thermostat 45 and an ice level sensing switch 48 operated by a feeler arm 49 (FIG. 2). Arm 49, as taught in the aforementioned Baker et al. and Shaw patents, is raised and lowered during each ice maker harvesting cycle to open and close switch 48, this switch being held open if the collection of ice in the receptacle 22 prevents the feeler arm 49 from returning to its lower position thereby preventing the initiation of a subsequent harvesting cycle. Motor operated timer switch means 50 includes contacts 53 and 54 for connecting motor 20 across lines L1, L2 during a harvesting cycle and contacts 54 and 55 for timed energization of water pump 36 during a harvesting cycle. The hot gas solenoid valve 41 is connected to contact 52 of the thermostat 45 and in parallel with the feeler arm switch 48 and the ice maker motor 20 so that whenever the thermostat 45 senses a predetermined below-freezing temperature in the ice mold, the solenoid valve is opened. In normal ice making operation, opening of contacts 53, 54 at the end of an ice making cycle deenergizes the solenoid valve 41. Normally, switch 45 opens contact 52 prior to this time. Back contact 41 of the switch 45 energizes fan 30 during normal refrigerating operation. Preferably, the contact 51 to operate fan is made before the harvest cycle is complete, so there is a brief period, usually one-half to two minutes, in which fan is running though still in defrost.
Considering the operation of the ice maker under the control of the circuitry of FIG. 5, if the ice bin is not filled with ice, the switch 48 is closed. At the time a new charge of water has been added to the mold, switch arm 56 of the thermostat 45 is engaged with contact 51 and fan 30 is energized. The compressor 8 is operating since it is connected directly across lines L1, L2 while the hot gas solenoid valve 41 is closed. Refrigeration is produced by the operation of the compressor to cause the evaporator sections 23 and 24 to go to below-freezing temperatures. The ice mold is cooled, causing the water in the mold to freeze. At the same time, the evaporator section 23 lowers the temperature of the freezer compartment.
When the temperature of the ice mold reduces to a below-freezing temperature, such as about 4 F assuring that the ice cubes are frozen, the thermostat 45 engages contact 52 thereby opening the fan circuit and energizing the ice maker motor 29 to close contacts 53 and 54 to open solenoid valve 41. The motor and ice ejection mechanism is then stalled by the bond between the ice pieces and the cavity walls until the hot gas flowing through the hot gas conduit into the mold and evaporator sections warms the mold to an ice releasing temperature. The ice maker motor 20 then runs driving the timer switch 50, energization of the motor being assured by the holding circuit through the contacts 53 and 54 of the timer switch so as to continue operation of the ice maker motor 20 regardless of the position of the thermostat switch 45 and feeler arm switch 48. After ejection of the ice pieces, a second circuit is established through contact 55 of the timer switch 50 to energize the water supply pump 36 for a period sufficient to fill the mold with a fresh charge of water. During completion of the ice maker harvesting cycle, the hot gas solenoid valve 41 is closed by opening of switch contacts 53 and 54, and the thermostat switch returns to its normal position engaging contact 51 in which the fan 30 is energized. It will be noted that the compressor runs continuously to either refrigerate or heat the evaporator sections and defrost is accomplished simultaneously with each ice cube harvesting cycle.
If the ice bin is full, so that the ice level switch 48 is held open, periodic defrosting of the evaporator section 23 is accomplished even though the ice maker does not operate. When the thermostat 45 senses the below-freezing temperature completing a circuit through contact 52, the hot gas valve 41 is energized, but since the ice level switch 48 is open the ice maker motor is not energized. Heating of both evaporator sections continues until the thermostat 45 senses the upper operating temperature of the mold thermostat. Desirably, this upper temperature is below 32 F., as for example about 24 F., in order to avoid cube thawing while also assuring defrosting of the evaporator section 23 which has a much lower thermal mass than the ice mold. Breaking of the thermostat contact 52 ends the defrost cycle and places the system back into a refrigeration cycle.
From the above description it will be seen that there is provided an automatic ice service refrigerator which eliminates the use of electric mold heating means and separate defrost heating means and provides for complete control of both the ice maker and the refrigeration system through refrigeration and defrost cycles by means of a single thermostat associated with the ice maker.
While there has been shown and described what is believed to be a preferred embodiment of the invention, it is to be understood that the invention is not limited thereto and it is intended by the appended claims to cover all such modifications as fall within the true spirit and scope of the invention. 7
1. A refrigerator comprising:
a freezer compartment containing an ice maker;
said ice maker including a mold, ejecting means for discharging ice pieces from said mold and thermostat means for periodically initiating operation of the ice maker through a harvesting cycle upon the sensing of a below-freezing mold temperature;
a refrigeration system including a compressor, a condenser, flow restricting means and an evaporator connected in closed series flow relationship;
said evaporator including a first section in heat exchange relationship with said ice maker mold and a second section for cooling said compartment;
conduit means including a valve connecting the compressor output to said evaporator for conducting hot gaseous refrigerant to said evaporator;
circuitry including said thermostat for opening said valve to conduct hot gaseous refrigerant through both evaporator sections during said harvesting cycle for heat releasing ice pieces from said mold and defrosting said second evaporator section; and
fan means for circulating freezer compartment air over said second evaporator section and means for rendering said fan inoperable during the major portion of a harvesting cycle.
2. A refrigerator according to claim 1 including an above-freezing compartment, containing a water storage reservoir and pump means operable to supply a charge of water from said reservoir to said ice maker during a harvesting cycle.
3. An automatic ice service refrigerator comprising:
a below-freezing storage compartment containing an ice maker and an ice storage receptacle;
said ice maker including a mold, ejecting means for discharging ice pieces from said mold and control means for periodically controlling the ice maker through a harvesting cycle including successive steps of discharging ice pieces from the mold and supplying water to said mold after ejection of the ice pieces, a motor for operating said ejecting and control means;
a refrigeration system including a compressor, a condenser, flow restricting means and an evaporator connected in closed series flow relationship;
said evaporator including a first section in heat exchange relationship with said ice maker mold and a second section mounted in the upper portion of said below-freezing compartment adjacent said ice maker;
conduit means including a valve connecting the compressor output to said evaporator for conducting hot gaseous refrigerant to said evaporator; and
control circuitry including a single control thermostat responsive to the freezing of water in said mold for energizing said motor to initiate a harvesting cycle and opening said valve to conduct hot gaseous refrigerant through both evaporator sections during said harvesting cycle.
4. A refrigerator according to claim 3 including switch means for preventing energization of said motor when said ice storage receptacle is full while permitting defrosting of said second evaporator section.